What is wrong with my body?

Everyone's heard of the show "I didn't know I was pregnant" right? Well when I heard of it I was like "how could you NOT KNOW you were pregnant?" Well I think I understand now. Now please no one judge me, but I'm supposed to be about 9 wks. I have taken so many HPTs, I even went to the dr at 5 wks and they did a blood test and it said I wasn't prego. But my stomach was harder, I missed a period and my cervix closed (I check my cervix during my cycle, weird I know, but closed is a sign of pregnancy). I've had basically every symptom, besides morning sickness I just get nausea. My stomach has gotten harder and a bit bigger, how could I be pregnant and not have it show up? I've now missed two periods and my mom just told me today she thinks I'm just getting fat. I'm a curvy skinny girl, all my weight is in my ass, thighs and boobs. I don't gain weight well, I've stayed at 130-135 for the last year and a half, now I've gained 5+ lbs in two months! I'm afraid something is wrong if I am pregnant, my husband is very worried about it, feels like he failed me. I go back to the dr tomorrow, anyone else kind of experienced this??? Someone please help me!